Unitized fibrous concrete reinforcement

ABSTRACT

The present invention relates to a fibrous construct which is used in providing cementitious mixtures supplemental and reinforcing strength upon setting, and more particularly, to a unitized fibrous construct which comprises a plurality of oriented reinforcing fibrous components, wherein the fibrous components can be cut to a predetermined and finite cut length upon formation and remain in a plural parallel form until such point the unitized fibrous substrate is incorporated and subjected to mechanical agitation during preparation of a cementitious blend or mixture.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of U.S. Provisional PatentApplication No. 60/442,574, filed Jan. 24, 2003, No. 60/442,672, filedJan. 24, 2003, No. 60/474,039, filed May 29, 2003, and No. 60/474,049,filed May 29, 2003.

TECHNICAL BACKGROUND

This invention relates to a fibrous construct which is used in providingcementitious mixtures supplemental and reinforcing strength uponsetting, and more particularly, to a unitized fibrous construct whichcomprises a plurality of oriented reinforcing fibrous components havinga finite cut length, said finite cut length providing a useful means foraccurately dosing cementitious mixtures. In one embodiment, acircumferential retaining element provides temporary retention of theoriented reinforcing fibrous components until such point the unitizedfibrous substrate is incorporated and subjected to mechanical agitationduring preparation of a cementitious blend or mixture. In an alternateembodiment, a binding agent is employed.

BACKGROUND OF THE INVENTION

Many proposals have been made to reinforce, strengthen, or otherwisebeneficially alter the properties of cementitious mixtures by applyingand/or incorporating various types of fibrous components, includingasbestos, glass, steel, as well as synthetic polymer fibers to aqueousbased concrete mixes prior to the curing of the concrete. The types ofpolymer fibers in use or proposed for use include those composed ofnatural and synthetic composition.

As is evident in the prior art, individual fibrous components are wellknown in terms of their performance modifying attributes. Relativelylarge diameter fibers, for example, in excess of 40 to 60 microns indiameter, can be added to a cementitious mixture such as a wet concreteblend, dispersed in the blend by mechanical agitation, followed bypouring and curing of the concrete. Large diameter fibers serve toreinforce the concrete after it has been cured, by providing additionaltensile strength and minimizing impact damage and crack propagation.Small diameter fibers, typically less than 30 to 40 microns in diameter,and having a relatively high surface area, are commonly added toconcrete mixes in order to reduce the development of small cracks in theconcrete during the curing period. The problem of crack development isknown to occur as a result of uneven curing of the concrete.

The fibrous components used typically in the practice of reinforcingcementitious mixtures include specifically thermoplastic syntheticfibers of finite staple length, such as polypropylene staple fibers.Thermoplastic staple fibers are produced by a well known and economicalmelt spinning process, in which molten polymer is extruded through a diehaving a plurality of small openings to produce a tow of continuousthermoplastic filaments of a controlled diameter. The filaments arecooled and drawn or elongated to increase tensile strength. A size orfinish is usually applied to the filaments, followed by drying andcutting into the desired length to provide bundles of individual fibers.The use of polypropylene fibers is desirable for several reasons,including low raw material cost, beneficial physical properties such asmalleability, and the non-reactive chemical properties of the polymer inthe adverse environments frequently encountered in cementitious mixtures(i.e. strongly alkaline pH).

While the functional performance of the reinforcing fibrous componentsis beneficial, the means for the quantitative measurement, physicaladdition and homogenous distribution of the reinforcing fibrouscomponents into a cementitious mixture is not without issue. Staplelength fibers, as have been conventionally used, are provided in thesame form as such are manufactured from the fiber formation line, whichincluded agglomerates of various size and weight, tangles or knots ofintermingled staple fibers, and numerous individual staple fibers thatare in and of themselves prone to release randomly. Due to the variableand unpredictable form conventional reinforcing fibrous components haveheretofore been provided for end-use consumption, such as at aconstruction work-site, the accurate and reproducible dosing ofreinforcing fibrous component into sequential batches of cementitiousmixtures has been dubious at best. Further complicating the actualutilization of the reinforcing fibrous components, numerous syntheticthermoplastic polymers used in the formation of suitable staple fibersare inherently hydrophobic in nature. As a result, difficulties canarise in obtaining a uniform dispersion and blending of the reinforcingfibrous component throughout hydrous cementitious mixtures usingconventional mixing equipment.

Prior attempts to address the issue described have focused on the use ofbinding agents. U.S. Pat. No. 5,399,195, incorporated herein byreference, discloses the addition of small amounts of fine (less than 30microns) polymer fibers to concrete. During production, the filamentsare treated with a topical wetting agent. After the filaments arechopped into staple-length fibers, the wetting agent holds or binds thestaple fibers together in the form of micro-bundles. The micro-bundlesremain relatively stable during handling, and when the fibers are addedto the concrete mix, the wetting agent promotes dispersion of thefibers. U.S. Pat. No. 6,258,159, also incorporated herein by reference,attempts to address the forming of micro-bundles of fibers byincorporation of binding agents into the staple fibers themselves duringthe melt-extrusion process.

The use of binding agents, whether internal or externally applied, whileimproving in-part issues inherent of individual staple fibers, suchpractices have not obviated such problems as random agglomerate size,and further, the use of binding agents has introduced additionalproblems. Most notably, the corresponding performance of the bindingagent is based upon application of the binding agent to thereinforcement fibrous components such that the binding agent is bothuniformly applied to the majority of the fibers so as to obtainequivalency within the batch, and that no excess binding agent isintroduced as such will adversely effect the ability of thereinforcement fibrous components to disengage and distributehomogeneously. One other determent encountered in the use of bindingagents is that air is often entrained within the micro-bundles uponapplication and agglomeration of the staple fibers. When suchmicro-bundles are subjected to mechanical mixing, the entrained air isreleased as a foam, a foam that reasonably compromises the ability ofthe cementitious mixture to cure uniformly.

As is evident in the industry, a unmet need exists for a means ofintroducing reinforcing fibrous components into a cementitious mixturesuch that the reinforcing fibrous components exhibit the attributes ofuniform and predictable presentation for use, ability to be homogenousdistributed during mechanical agitation, and does not introduce anadverse chemical agent which can compromise the performance of theresulting cementitious matrix.

SUMMARY OF THE INVENTION

The present invention relates to a fibrous construct which is used inproviding cementitious mixtures supplemental and reinforcing strengthupon setting, and more particularly, to a unitized fibrous constructwhich comprises a plurality of oriented reinforcing fibrous componentswhich can be cut to a predetermined and finite cut length uponformation, and remain in a plural parallel form until such point theunitized fibrous substrate is incorporated and subjected to mechanicalagitation during preparation of a cementitious blend or mixture. Thereinforcing fibrous components can be combined with a circumferentialretaining element, said circumferential retaining element providingtemporary retention of the oriented reinforcing fibrous components. Theunitized fibrous construct is endowed with inherent and improveddispensability and dispersability of the associated reinforcing fibrouscomponent into organic or inorganic cementitious matrixes, such asconcrete, mortar, plaster, etc.

In one embodiment, the unitized fibrous construct of the presentinvention is formed from two or more reinforcing fibrous components offinite staple length and essentially parallel orientation and caninclude a circumferential retaining element. In another embodiment, theunitized fibrous construct of the present invention is formed from twoor more reinforcing fibrous components of infinite length andessentially parallel orientation and can include a circumferentialretaining element. The compositions of the reinforcing fibrous componentis selected from the group consisting of synthetic polymers, naturalpolymers, and the combinations thereof, and are not necessarily of thesame polymeric composition, denier, finite staple length, orfunctionality. The circumferential retaining element describes a routeabout the combined two or more essentially parallel reinforcing fibrouscomponents, thereby maintaining both the combination and essentiallyparallel orientation of the reinforcing fibrous components. Once formed,the circumferential retaining element aids in maintaining the integrityof the unitized fibrous construct, and the reinforcing fibrous componenttherein, for purposes of shipment, measurement, and dosing into acementitious mixture. Preferably, the circumferential retaining elementcircumscribes no more than 80% of the total surface area of the unitizedfibrous construct; more preferably circumscribes no more than 50% of thetotal surface area of the unitized fibrous construct; and mostpreferably circumscribes no more than 30% of the total surface area ofthe unitized fibrous construct, wherein the total surface area isdefined as the overall length and circumference of the unitized fibrousconstruct. Limiting the circumferential retaining element serves toexpose the significant and useful proportion oriented reinforcingfibrous components within the unitized fibrous constructs to theexternal environment. Upon mechanical agitation of the unitized fibrousconstruct in a cementitious mixture, the circumferential retainingelement is disrupted, allowing for the homogenous release, distributionand dispersion of the reinforcing fibrous component into the overallcementitious mixture.

The circumferential retaining element is selected from suitablematerials, such as thermoplastic, thermoset and soluble resins, whichare subject to mechanical failure when a corresponding stress and/orsolvency threshold is exceeded. Various geometries may be employed inthe application of the circumferential retaining element, includingwithout limitation, continuous or discontinuous filaments, ribbons, orsheets, which circumscribe the combined, essentially parallelreinforcing fibrous components. The circumferential retaining elementmay comprise one or more continuous or discontinuous filaments, ribbons,or sheets of varying thicknesses that retain the reinforcing fibrouscomponents by a plurality of wrapping techniques so as to expose more orless fiber to the external environment. It is within the purview of thepresent invention that the composition of the circumferential retainingelements and of one or more of the reinforcing fibrous components neednot necessarily be the same.

It should be noted that the reinforcing fibrous components, as well asthe resulting unitized fibrous constructs, can be treated withperformance modifying additives, such as represented by the topicalapplication of a material flow-enhancing lubricant. Further, temporarybinding agents, including water-soluble chemistries such as polyvinylalcohol, can be used in conjunction with the circumferential bindingelement.

The present unitized fibrous construct can also be formed by theinterlocking of the reinforcing fibrous components by chemical and/ormechanical means. Such suitable means include the application of abinder that exhibits sufficient durability to maintain the pluralparallel form, and yet is discernable or otherwise deficient indurability when subjected to an appropriate mechanical or solvationforce. Preferably, the chemical and/or mechanical interlocking meanscomprises no more than 80% of the total surface area of the unitizedfibrous construct; more preferably comprises no more than 50% of thetotal surface area of the unitized fibrous construct; and mostpreferably comprises no more than 30% of the total surface area of theunitized fibrous construct, wherein the total surface area is defined asthe overall length and circumference of the unitized fibrous construct.Limiting the chemical and/or mechanical interlocking means serves toexpose the significant and useful proportion of the oriented reinforcingfibrous components within the unitized fibrous constructs to theexternal environment.

Upon final formation of the unitized fibrous constructs, the constructscan be readily packaged through an automatic packaging system orcontainerized in bulk. The latter packaging allows for a quantity ofunitized fibrous constructs to being accurately and reproduciblyaugured, scooped or blended into a cementitious mixture at a mixingstation, for example, through an automated gravimetric dispensingsystem.

Other features and advantages of the present invention will becomereadily apparent from the following detailed description, theaccompanying drawings, and the appended claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a photograph of a representative unitized fibrous construct asformed in accordance with the present invention, approximate dimensionsare an overall circumference of 25 mm and a length of 18 mm;

FIG. 2 is a photomicrograph of the same unitized fibrous construct asshown in FIG. 1, wherein the plurality of reinforcing fibrous componentsand the single circumferential retaining element are more specificallydepicted;

FIG. 3 is a photograph of a representative unitized fibrous construct asformed in accordance with the present invention; and

FIG. 4 is a photomicrograph of the same unitized fibrous construct asshown in FIG. 3, wherein the plurality of reinforcing fibrous componentsand the single circumferential retaining element are more specificallydepicted.

DETAILED DESCRIPTION

While the present invention is susceptible of embodiment in variousforms, hereinafter is described a presently preferred embodiment of theinvention, with the understanding that the present disclosure is to beconsidered as an exemplification of the invention, and is not intendedto limit the invention to the specific embodiment illustrated.

Finite staple length fibers are routinely used as a reinforcement meansin cementitious mixtures so as to render a corresponding curedcementitious construct incorporating such fibers more resistant tostructural defect and failure. Due to difficulties encountered in theactual handling and homogenous incorporation of the finite staple lengthfibers experienced in preparing a cementitious mixture, the presentinvention is directed to a means for facilitating such preparation in anaccurate and reproducible way.

A unitized fibrous construct which comprises a plurality of orientedreinforcing fibrous components is formed such that the fibrouscomponents have an essentially parallel orientation. The unitizedconstruct is provided temporary retention of the reinforcing fibrouscomponents, which can take the form of a circumferential retainingelement, until such point the unitized fibrous substrate is incorporatedand subjected to mechanical agitation during preparation of acementitious blend or mixture. The unitized fibrous construct is endowedwith inherent and improved dispensability and dispersability of theassociated reinforcing fibrous component into organic or inorganiccementitious matrixes, such as concrete, mortar, plaster, etc.

In one embodiment, the unitized fibrous construct of the presentinvention is formed from two or more reinforcing fibrous components offinite staple length and essentially parallel orientation, wherein thecomposition of such staple fibers is selected from the group consistingof synthetic polymers, including, but not limited in polyesters,polyolefins, polyamides, and the combinations thereof, as well asnatural fibers, including, but not limited to rayon, cotton, pulp, flax,and hemp and the combinations thereof. Preferably, the composition ofthe reinforcing fibers is selected from the synthetic polymersincluding, without limitation, thermoplastic and thermoset polymers. Aparticularly preferred embodiment of the present invention is directedto reinforcing staple fibers comprising polyolefin thermoplastic resins.In another embodiment, the unitized fibrous construct of the presentinvention is formed from two or more reinforcing fibrous components ofinfinite length and essentially parallel orientation, wherein thecomposition of such fibers is selected from the group consisting ofsynthetic polymers, natural polymers, and the combinations thereof. Itis within the purview of the present invention that the individualreinforcing fibrous components as incorporated in the unitized fibrousconstruct need not necessarily be of the same polymeric composition,denier, finite staple length, or functionality. It is further within thepurview of the present invention that either a portion of thereinforcing fibrous components or all of the reinforcing fibrouscomponents may be placed under tension by means of twisting thereinforcing fibrous components or by other means. Placing tension onsome or all of the reinforcing fibrous components causes the fibrouscomponents to burst or pop upon mechanical agitation, which enhances thefiber distribution within a cementitious mixture.

In this embodiment, the unitized fibrous construct further includes acircumferential retaining element. The circumferential retaining elementdescribes a route about the combined two or more essentially parallelreinforcing fibrous components, thereby maintaining both the combinationand essentially parallel orientation of the reinforcing fibrouscomponents. Once formed, the circumferential retaining element aids inmaintaining the integrity of the unitized fibrous construct, and thereinforcing fibrous component therein, for purposes of shipment,measurement, and dosing into a cementitious mixture. Upon mechanicalagitation, and optionally exposure to appropriate solvents, of theunitized fibrous construct in a cementitious mixture, thecircumferential retaining element is disrupted, allowing for thehomogenous release, distribution and dispersion of the reinforcingfibrous component into the overall cementitious mixture.

The circumferential retaining element is selected from suitablematerials, such as thermoplastic, thermoset and soluble resins, whichare subject to mechanical failure when a corresponding stress and/orsolvency threshold is exceeded. Various geometries may employed in theapplication of the circumferential retaining element, including withoutlimitation, continuous or discontinuous filaments, ribbons, or sheets,which circumscribe the combined, essentially parallel reinforcingfibrous components. The circumferential retaining element may compriseone or more continuous or discontinuous filaments, ribbons, or sheets ofvarying thicknesses that retain the reinforcing fibrous components by aplurality of wrapping techniques so as to expose more or less fiber tothe external environment. It is within the purview of the presentinvention that the composition of the circumferential retaining elementsand of one or more of the reinforcing fibrous components need notnecessarily be the same.

In one embodiment, the reinforcing fibrous components are retained bytwo thin circumferential retaining elements in a double helix wrappingtechnique, whereby two circumferential retaining elements criss-crossback and forth about the circumference of the fibrous components. It iswithin the purview of the present invention that the composition of thecircumferential retaining elements and of one or more of the reinforcingfibrous components need not necessarily be the same. Preferably, thecircumferential retaining element circumscribes no more than 80% of thetotal surface area of the unitized fibrous construct; more preferablycircumscribes no more than 50% of the total surface area of the unitizedfibrous construct; and most preferably circumscribes no more than 30% ofthe total surface area of the unitized fibrous construct. Limiting thecircumferential retaining element serves to expose the orientedreinforcing fibrous components within the unitized fibrous constructs tothe external environment. In addition, the exposure of the fibrouscomponents allows for more effective disruption of the unified fibrousconstruct when subjected to mechanical or solvent disruption.

A number of suitable methodologies exist for the formation of unitizedfibrous constructs in accordance with the present invention. Apreferred, though non-limiting, method is taught in part by U.S. Pat.No. 4,228,641, incorporated herein by reference, wherein a twinecomprised of a core bundle of synthetic monofilaments is circumscribedby a synthetic material in a thin band form spirally wound about themonofilaments. It has been found by the inventors of the presentinvention that by practice of the '641 method, with subsequent andrepeated scission of the continuous twine construct at or between eachiteration of the spiral winding that finite length unitized fibrousconstructs are formed which are suitable for practice in light of thepresent invention.

The dimensions of the unitized fibrous construct is defined in terms of;the overall circumference, as based on the quantity and relative denierof the individual reinforcing fibrous components, and of length, asbased on the greatest finite staple length of the cumulative combinationof reinforcing fibrous components. Suitable overall circumferences andlengths of unitized fibrous constructs formed in accordance with thepresent invention may reasonably range from 3 mm to 150 mm and from 8 mmto 100 mm, respectively. In a presently preferred embodiment forstandard practices, unitized fibrous constructs exhibit an overalldiameter of between 3 mm and 30 mm and lengths of between 12 mm and 50mm may be utilized.

In accordance with the present invention, the reinforcing fibrouscomponents may also be of infinite length, wherein the reinforcingfibrous components are combined in an essentially parallel orientation,whereby one or more circumferential retaining elements circumscribesabout the overall circumference of the continuous reinforcing fibrouscomponents, or whereby one or more chemical and/or mechanicalinterlocking means circumscribes about the overall circumference of thecontinuous reinforcing fibrous components. Such a formation allows thecontinuous unitized reinforcing fibrous components to be available in acontinuous roll form or packaged in a continuous lap formation. Further,the continuous unitized reinforcing fibrous components are comprised ofa series of segmented perforations or weakened points along thecontinuous formation so that the desired portion may be selected anddetracted from the roll form.

It should be noted that the reinforcing fibrous components, as well asthe resulting unitized fibrous constructs, can be treated withperformance modifying additives, such as represented by the topicalapplication of a material flow-enhancing lubricant and temporary bindingagents, such as water-soluble chemistries.

The interlocking of the reinforcing fibrous components embodying thepresent invention can also be by chemical and/or mechanical means formsthe unitized fibrous construct. Such suitable means include theapplication of a binder that exhibits sufficient durability to maintainthe plural parallel form, and yet is discernable or otherwise deficientin durability when subjected to an appropriate external force.Preferably, the chemical and/or mechanical interlocking means comprisesno more than 80% of the total surface area of the unitized fibrousconstruct; more preferably comprises no more than 50% of the totalsurface area of the unitized fibrous construct; and most preferablycomprises no more than 30% of the total surface area of the unitizedfibrous construct. Limiting the chemical and/or mechanical interlockingmeans serves to expose the significant and useful proportion of theoriented reinforcing fibrous components within the unitized fibrousconstructs to the external environment. In addition, the exposure of thefibrous components allows for more effective disruption of the unifiedfibrous construct when subjected to mechanical or solvent disruption.

Once formed, an interlocking means or agent, such as a polyvinyl alcoholor other water-soluble binding agent aids in maintaining the integrityof the unitized fibrous construct, and the reinforcing fibrous componenttherein, for purposes of shipment, measurement, and dosing into acementitious mixture. Upon mechanical agitation, and optionally exposureto appropriate solvents, of the unitized fibrous construct in acementitious mixture, the interlocked structure is disrupted, allowingfor the homogenous release, distribution and dispersion of thereinforcing fibrous component into the overall cementitious mixture.

Upon final formation of the unitized fibrous constructs, the constructscan be readily packaged through an automatic packaging system orcontainerized in bulk. The latter packaging allows for a definedquantity of unitized fibrous constructs to being accurately andreproducibly augured, scooped or blended into a cementitious mixture atmixing station, through an automated gravimetric dispensing system.

From the foregoing, it will be observed that numerous modifications andvariations can be affected without departing from the true spirit andscope of the novel concept of the present invention. It is to beunderstood that no limitation with respect to the specific embodimentsillustrated herein is intended or should be inferred. The disclosure isintended to cover, by the appended claims, all such modifications asfall within the scope of the claims.

1. A method of improving the properties of a cementitious mixture,wherein said method comprises the steps of: a. providing a cementitiousmixture; b. providing unitized fibrous constructs, each of said unitizedfibrous constructs being comprised of: i. two or more reinforcingfibrous components; ii. one or more circumferential retaining elements;iii. wherein said reinforcing fibrous components are combined in anessentially parallel orientation and said circumferential retainingelement extends spirally and circumscribes about an overallcircumference described by said combined and essentially parallelreinforcing fibrous components, said circumferential retaining elementcircumscribing no more than 80% of the total circumferential surfacearea of said unitized fibrous constructs; c. adding into saidcementitious mixture a quantity of unitized fibrous constructs so as toform a cementitious mixture and unitized fibrous construct blend; and d.mechanically agitating said cementitious mixture/unitized fibrousconstruct blend so as to disrupt said circumferential retaining elementsand disperse said reinforcing fibrous components into said cementitiousmixture.
 2. A method as in claim 1, wherein said fibrous constructs arenatural fibers.
 3. A method as in claim 2, wherein said natural fibersare selected from the group consisting of rayon, cotton, pulp, flax,hemp, and the combinations thereof.
 4. A method as in claim 1, whereinsaid fibrous constructs are synthetic fibers.
 5. A method as in claim 4,wherein said synthetic fibers are selected from the group consisting ofpolyesters, polyolefins, polyamides, and the combinations thereof.
 6. Amethod as in claim 1, wherein said unitized fibrous constructs exhibitan overall circumference of between about 3 mm to 150 mm.
 7. A method asin claim 6, wherein said unitized fibrous constructs exhibit an overallcircumference of between about 3 mm to 30 mm.
 8. A method as in claim 1,wherein said unitized fibrous constructs exhibit a length of betweenabout 8 mm to 100 mm.
 9. A method as in claim 8, wherein said unitizedfibrous constructs exhibit a length of between about 12 mm to 50 mm. 10.A method as in claim 1, wherein said reinforcing fibrous compoundsexhibit a finite staple length.
 11. A method as in claim 1, wherein saidreinforcing fibrous components exhibit an infinite length.
 12. A methodas in claim 1, wherein a portion or all of said reinforcing fibrouscomponents are placed under tension.
 13. A method as in claim 11,wherein said unitized fibrous constructs comprise perforated segments.14. A method of improving the properties of a cementitious mixture,wherein said method comprises the steps of: a. providing a cementitiousmixture; b. providing unitized fibrous constructs, each of said unitizedfibrous constructs being comprised of: i. two or more reinforcingfibrous components; ii. an interlocking means; iii. wherein saidreinforcing fibrous components are combined in an essentially parallelorientation and said interlocking means extends spirally and is appliedabout an overall circumference described by said combined andessentially parallel reinforcing fibrous components, said interlockingmeans comprising no more than 80% of the total circumferential surfacearea of the unitized fibrous constructs; c. adding into saidcementitious mixture a quantity of unitized fibrous constructs so as toform a cementitious mixture and unitized fibrous construct blend; and d.mechanically agitating said cementitious mixture/unitized fibrousconstruct blend so as to disrupt said interlocking means and dispersesaid reinforcing fibrous components into said cementitious mixture. 15.A method as in claim 14, wherein said fibrous constructs are naturalfibers.
 16. A method as in claim 15, wherein said natural fibers areselected from the group consisting of rayon, cotton, pulp, flax, hemp,and the combinations thereof.
 17. A method as in claim 14, wherein saidfibrous constructs are synthetic fibers.
 18. A method as in claim 14,wherein said synthetic fibers are selected from the group consisting ofpolyesters, polyolefins, polyamides, and the combinations thereof.
 19. Amethod as in claim 14, wherein said unitized fibrous constructs exhibitan overall circumference of between about 3 mm to 150 mm.
 20. A methodas in claim 19, wherein said unitized fibrous constructs exhibit anoverall circumference of between about 3 mm to 30 mm.
 21. A method as inclaim 14, wherein said unitized fibrous constructs exhibit a length ofbetween about 8 mm to 100 mm.
 22. A method as in claim 21, wherein saidunitized fibrous constructs exhibit a length of between about 12 mm to50 mm.
 23. A method as in claim 14, wherein said interlocking means is abinder.
 24. A method as in claim 14, wherein a portion or all of saidreinforcing fibrous components are placed under tension.
 25. A method asin claim 14, wherein said reinforcing fibrous components exhibit afinite staple length.
 26. A method as in claim 14, wherein saidreinforcing fibrous components exhibit an infinite length.